Apparatus, system, method and computer-readable medium for isolating chemical exchange saturation transfer contrast from magnetization transfer asymmetry under two-frequency RF irradiation

Abstract

Apparatus, system, method and computer-readable medium for isolating chemical exchange saturation transfer contrast from magnetization transfer asymmetry under two-frequency RF irradiation. A two-pool model for magnetization transfer (MT) can be established fully based on Provotorov's theory of saturation, and then extended to the situation of simultaneous two-frequency RF irradiation. Numerical simulations and experimental results demonstrate that two-frequency RF irradiation can make MT effects independent of irradiation frequency over a wide range, and thus can suppress MT asymmetry. Exemplary embodiments can be provided to isolate chemical exchange saturation transfer (CEST) contrast from MT asymmetry contrast by using the two-frequency RF irradiation technique. A further embodiment can isolate a narrow-frequency spectrum MT mechanism from a broad-frequency spectrum MT mechanism.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S)[0001]This application relates to and claims priority from U.S. Provisional Patent Application No. 61 / 564,016, filed on Nov. 28, 2011, the entire disclosure of which is incorporated herein by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH[0002]Portions of the material described herein were funded, at least in part, by National Institute of Health under grant numbers K25AR060269 and R21AR055724, and by National Science Foundation under grant number CHE0957586. Therefore, the Federal Government may have certain rights to the invention.FIELD OF THE DISCLOSURE[0003]Exemplary embodiments of the present disclosure relate to systems, methods and computer-readable mediums for isolating chemical exchange saturation transfer contrast from magnetization transfer asymmetry under two-frequency radio-frequency (“RF”) irradiation.BACKGROUND INFORMATION[0004]Magnetization transfer (“MT”) is, in general, a macroscopic phenomenon in...

AI Technical Summary

Benefits of technology

The patent describes a method for measuring the frequencies of water protons in a sample using magnetic resonance imaging (MRI). The method includes using two frequencies to irradiate the sample and measuring the residual polarization. By measuring the changes in frequency caused by the irradiation, the method can identify the direct saturation of water protons and averaging two frequencies at local minima to improve accuracy. The method can also correct for CEST contrast by shifting the plot to center on zero. Additionally, the method can measure a third frequency to further refine the CEST contrast by eliminating MT effects. Overall, the method provides a way to measure the frequencies of water protons in a sample without requiring an additional scan for a B0 map.

Problems solved by technology

In tissues and organs, CEST can occur together with MT, which can make the quantitative measure of CEST difficult.

It can be difficult, however, to separate the two effects if an asymmetry in MT exists, which can be very common in biological tissues.

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